* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Roboto, Arial, sans-serif;
}
:root {
    --main: #0F4C81;
    --dark: #222;
    --gray: #666;
    --light: #f5f7fa;
    --white: #fff;
}
body {
    color: var(--dark);
    line-height: 1.6;
    background: var(--light);
}
.container {
    width: 92%;
    max-width: 1200px;
    margin: 0 auto;
}
a {
    text-decoration: none;
    color: inherit;
}
ul {
    list-style: none;
}
.btn {
    display: inline-block;
    padding: 12px 28px;
    background: var(--main);
    color: #fff;
    border-radius: 4px;
    transition: 0.3s;
    border: none;
    cursor: pointer;
}
.btn:hover {
    background: #0c3d68;
}
.btn-light {
    background: #fff;
    color: var(--main);
    border: 1px solid var(--main);
}
.btn-light:hover {
    background: var(--main);
    color: #fff;
}

/* 头部导航 */
.header {
    background: #fff;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 999;
}
.nav-wrap {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}
.logo {
    font-size: 24px;
    font-weight: 700;
    color: var(--main);
}
.nav-list {
    display: flex;
    gap: 35px;
}
.nav-list a {
    font-size: 15px;
    font-weight: 500;
    padding: 8px 0;
    position: relative;
}
.nav-list a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--main);
}
.mobile-menu {
    display: none;
    font-size: 24px;
}

/* 轮播Banner */
.banner {
    height: 520px;
    background: linear-gradient(rgba(15,76,129,0.8),rgba(15,76,129,0.8)), url(../images/banner1.jpg) center/cover no-repeat;
    display: flex;
    align-items: center;
    color: #fff;
}
.banner-text h1 {
    font-size: 42px;
    margin-bottom: 20px;
    line-height: 1.2;
}
.banner-text p {
    font-size: 18px;
    margin-bottom: 30px;
    opacity: 0.9;
    max-width: 600px;
}

/* 通用区块 */
.section {
    padding: 70px 0;
}
.section-title {
    text-align: center;
    margin-bottom: 50px;
}
.section-title h2 {
    font-size: 32px;
    color: var(--main);
    margin-bottom: 12px;
}
.section-title p {
    color: var(--gray);
}

/* 首页产品卡片 */
.product-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}
.product-card {
    background: #fff;
    border-radius: 6px;
    overflow: hidden;
    box-shadow: 0 3px 10px rgba(0,0,0,0.08);
    transition: 0.3s;
}
.product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.12);
}
.product-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}
.product-info {
    padding: 20px;
}
.product-info h3 {
    font-size: 18px;
    margin-bottom: 10px;
}
.product-info p {
    color: var(--gray);
    font-size: 14px;
    margin-bottom: 15px;
}

/* 优势板块 */
.advantage {
    background: #fff;
}
.adv-grid {
    display: grid;
    grid-template-columns: repeat(4,1fr);
    gap: 25px;
    text-align: center;
}
.adv-item i {
    font-size: 40px;
    color: var(--main);
    margin-bottom: 20px;
}
.adv-item h4 {
    font-size: 18px;
    margin-bottom: 10px;
}

/* 产品页布局 */
.product-list-page {
    background: #fff;
}
.product-page-grid {
    display: grid;
    grid-template-columns: repeat(3,1fr);
    gap: 30px;
}

/* 关于我们 */
.about-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
}
.about-text h3 {
    font-size: 24px;
    color: var(--main);
    margin-bottom: 20px;
}
.about-text p {
    color: var(--gray);
    margin-bottom: 15px;
}

/* 联系我们 */
.contact-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}
.contact-info h3 {
    font-size: 24px;
    color: var(--main);
    margin-bottom: 25px;
}
.contact-item {
    margin-bottom: 20px;
    display: flex;
    align-items: flex-start;
    gap: 15px;
}
.contact-item i {
    font-size: 20px;
    color: var(--main);
    margin-top: 4px;
}
.form-item {
    margin-bottom: 20px;
}
.form-item input,
.form-item textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 15px;
}
.form-item textarea {
    height: 140px;
    resize: none;
}

/* 页脚 */
.footer {
    background: var(--dark);
    color: #ccc;
    padding: 50px 0 20px;
}
.footer-grid {
    display: grid;
    grid-template-columns: repeat(4,1fr);
    gap: 30px;
    margin-bottom: 40px;
}
.footer-col h4 {
    color: #fff;
    font-size: 18px;
    margin-bottom: 20px;
}
.footer-col li {
    margin-bottom: 10px;
}
.footer-col a:hover {
    color: var(--main);
}
.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: #333 solid 1px;
    font-size: 14px;
}

/* 响应式适配 */
@media (max-width: 992px) {
    .product-grid, .adv-grid, .footer-grid {
        grid-template-columns: repeat(2,1fr);
    }
    .product-page-grid {
        grid-template-columns: repeat(2,1fr);
    }
    .about-row, .contact-row {
        grid-template-columns: 1fr;
    }
}
@media (max-width: 768px) {
    .nav-list {
        display: none;
    }
    .mobile-menu {
        display: block;
    }
    .banner {
        height: 400px;
    }
    .banner-text h1 {
        font-size: 30px;
    }
}
@media (max-width: 576px) {
    .product-grid, .adv-grid, .product-page-grid, .footer-grid {
        grid-template-columns: 1fr;
    }
    .section {
        padding: 40px 0;
    }
}